The present invention generally relates to an anchor mechanism that is usable within a seat belt system.
FIG. 1 shows a typical three-point seat belt system 20 comprising a retractor 22, and a length of seat belt webbing 24 divided into a shoulder belt 26 and a lap belt 28. The lap belt 28 is anchored to the floor by a conventional anchor 30. The demarcation between the shoulder belt 26 and lap belt 28 is often defined by the tongue 32 which is inserted within a seat belt buckle 34, also anchored by an appropriate anchor mechanism such as 30a (which can be the same as anchor 30). The shoulder belt 26 is supported by a web guide 52 which can be part of a height adjusting mechanism 50 secured to a structural portion of the vehicle or to a frame of a seat. As is known in the art, the seat belt system can be secured to a frame 42 located within a seat back 44 of the seat 46 or secured as illustrated exterior thereto. The web guide 52 can alternatively be directly secured to a vehicle frame component 54 such as the B and C pillar.
Reference is now made to FIGS. 2 and 3 which show a prior art anchor mechanism such as 30 or 30a. This type of anchor mechanism is typically used to secure the buckle 34 or lap belt 28 to a vehicle structural member such as a floor or a seat frame. This or a similar type of anchor can also be used to connect the D-ring or web guide 52 to the height adjusting mechanism 50 or directly to a structural member 54 or seat frame 42 of a seat.
Anchor mechanisms such as 30 (or 30a) comprise a steel plate 60 having a circular first opening 62 and an oblong second opening 64. The plate 60 is typically fully coated with a anti-corrosive coating (not shown) such a dichromate, paint, zinc plating, etc. One end such as 66 of the plate, proximate an end of opening 64, is further coated with a three-dimensional, abrasion resistant, elastomeric coating 68 to prevent an anchor strap 70 from being abraded upon any rough metal corners. In the embodiment illustrated in FIGS. 2 and 3, the anchor strap 70 is made from a length of seat belt webbing. One end of the strap such as 72 is looped about end 66 and the coating 68. The other end 74 of the strap 70 is secured, in a known manner, to the buckle 34. Opening 64 can have alternate shapes such as circular and the anchor strap can be formed by a Bowden cable secured therein. The opening 62 is sized to receive a plastic bushing 80, having a passage or opening 84. The bushing provides a low friction surface for a fastener such as stepped bolt 82. The bushing 80 also reduces vibrational noise. Prior to installation of the anchor mechanism 30 within the vehicle, the bolt 82 is inserted within opening 84 and retained therein by a thin speed nut or star washer or similar fastener or retainer 90. The retainer 90 holds the bolt 82 to the plate 60 prior to installation.
The bolt 82 includes a narrow diameter threaded portion 92 with threads 92a, a shoulder 94, a larger diameter smooth portion or neck 96 and a head 98 capable of being twisted by a tool. The head 98 can take on many shapes, such as hexagonal, square or alternatively a screw driver slot 99 may be provided in the center of the head 98. During installation, the threaded portion 92 is received within a threaded opening 100 within the vehicle structural part generally referred to as 102. This part 102 can be the seat frame or B or C pillars or other part of the vehicle. The bolt 82 is subsequently fastened to the structural part 102 trapping the nut 90 between the shoulder 94 and the structural part 102. As can be appreciated, the threaded opening 100 can be formed within a threaded bolt 104 secured to the part 102 or, alternatively, the opening 106 of the part 102 can be tapped.
Subsequent to installation the plate 60 is received about the neck 96 of the fastener 82 and plate 60 is free to rotate and slide about the neck 96 to accommodate movement of the buckle 34 or shoulder belt 28 or other safety component secured thereto as the seat belt is secured about the occupant or if the seat 46 is moved from its nominal position. The longitudinal movement of the plate 60 is shown by arrow 110 and arrow 112 indicates that the plate can also rotate about the axis of the bolt 82.
However, as can be seen from the above, one of the deficiencies of the prior art design is that the bolt 82 is secured to the plate 60 by a separate retainer 90. Further, to permit the plate to rotate smoothly about the fastener 82, the separate bushing is required and if the attachment strap 70 is accomplished by seat belt webbing, the plate must further be coated with a protective coating 68 as well as protected by the anti-corrosive coating.
It is an object of the present invention to provide an improved anchor mechanism having a reduced parts count and one easier to install within the vehicle. A further object of the present invention is to provide an anchor mechanism having an integrally formed bolt retainer that is capable of securing an attachment bolt to an anchor plate prior to installation in the vehicle and one which breaks away from the anchor plate during installation into a vehicle (including a seat).
Accordingly, the invention comprises: an anchor mechanism comprising: a load bearing plate having first opening. The plate is coated by a coating material at least in the vicinity of the first opening. The coating material proximate the first opening is formed into a breakaway retaining ring which functions to retaining a fastening bolt to the coated plate prior to installation and which breaks away during installation of the anchor mechanism to a corresponding vehicle part. The plate may include a second opening secured to another seat belt component such as a buckle via an anchor strap or cable. The anchor mechanism can be used as a D-ring or web guide wherein the second opening comprises a narrow, arcuate web slot.
Many other objects and purposes of the invention will be clear from the following detailed description of the drawings.